Investigation and modelling of the effects of solidification time and grain refinement on the grain size of a sand-cast Al4Cu alloy

It is well known that adding small amounts of Ti and B into aluminium casting alloys increase the fluidity, feedability, strength, fatigue resistance and pressure tightness. These occur because of Ti and B within the master alloys create heterogeneous nucleation sites by forming such intermetallic compounds as TiB2, Al3Ti and AlB2. It is also known that the solidification time is influential on the formation of final grain size of aluminium cast parts. However the combining effects of both grain refining and solidification time has not been studied properly. Therefore, in this work, the effects of the grain refining and solidification time have been investigated on a sand-cast Al-4wt%Cu alloy. To determine solidification time effect, a tests mould having different section thickness has been used.